Amazon.com CEO Jeff Bezos asks his employees if they are "lazy or incompetent" and after a presentation once asked an engineer "Why are you wasting my life?"

Jack Dorsey, co-founder of Twitter and CEO of Square, stabbed his friend and Twitter co-founder Noah Glass in the back, figuratively, in the early days of the social media company when Dorsey insisted that Glass be pushed out.

Ruthless, cut-throat and shrewd. Those are all adjectives that come to mind when you read about Bezos and Dorsey -- two of the most influential men in technology -- in recent excerpts from two soon-to-be-released books.

New York Times writer Nick Bilton's "Hatching Twitter: A True Story of Money, Power, Friendship, and Betrayal" will be out on Nov. 5 and Bloomberg Businessweek writer Brad Stone's "The Everything Store: Jeff Bezos and the Age of Amazon" will hit later this month. In the last 48 hours, short excerpts from each book have been released and both paint fairly nasty images of the leaders.

Both pieces also paint pictures of complicated men. Dorsey, you learn, was an aspiring fashion designer and at one point was told by former Twitter CEO Ev Williams "You can either be a dressmaker or the C.E.O. of Twitter." Another interesting tidbit: "Friendstalker" was one of the names first kicked around for the 140-character service. Glass actually found the name for Twitter while flipping through a dictionary.

Bezos' backstory is a bit more emotional. Stone explains that Bezos was adopted and that his biological father Ted Jorgensen didn't even know of his son's business accomplishments. In fact, Stone was the one who told him about his son.

"Jorgensen said he didn't know who Jeff Bezos was and was baffled by my suggestion that he was the father of this famous CEO," Stone writes.